Magnitude 5.8 Earthquake Injures at Least 29 in Indonesia

17 August, 2025

A magnitude 5.8 undersea earthquake struck Indonesia's Central Sulawesi province, injuring at least 29 people, with two in critical condition. The quake, which occurred 15 kilometers north of the Poso district, was followed by multiple aftershocks. Most of the injured were attending a Sunday morning church service when the structure sustained damage. Indonesia, located on the Pacific 'Ring of Fire,' frequently experiences seismic activity. Authorities did not issue a tsunami warning following the tremor.

Unpacked:

Why was there no tsunami warning issued after this quake?

Tsunami warnings are only issued if an earthquake is strong enough and of the right type (usually shallow and with vertical motion) to displace large volumes of water. This quake, at magnitude 5.8, was not powerful enough or of the right characteristics to trigger a tsunami, according to Indonesian authorities.

How frequent are earthquakes in Central Sulawesi, and what is the recent history of major seismic events there?

Central Sulawesi is highly seismically active due to the Palu-Koro fault. A major event occurred in September 2018: a magnitude 7.5 earthquake followed by a tsunami killed over 4,340 people and caused massive destruction. Smaller quakes and aftershocks are common in the region.

What safety measures or building codes are in place in Indonesia to protect against earthquake damage, especially in churches and public buildings?

Indonesia has building codes intended to improve earthquake resistance, but enforcement varies, especially in rural areas. Many structures, including older churches, may not be built to modern standards, making them vulnerable during strong quakes. Efforts to upgrade buildings have increased after major disasters, but progress is uneven.

What support or aid is typically provided to victims and communities affected by earthquakes in Indonesia?

After earthquakes, the Indonesian government, local authorities, NGOs, and international organizations provide emergency aid, medical care, temporary shelter, and food. Long-term recovery includes rebuilding homes and infrastructure. However, challenges like damaged roads, communication breakdowns, and resource constraints can delay effective aid delivery.